drm/amdgpu: Replace numbers with PCI_EXP_LNKCTL2 definitions

Replace hard-coded magic numbers with the descriptive PCI_EXP_LNKCTL2
definitions.  No functional change intended.

Link: https://lore.kernel.org/r/20191112173503.176611-4-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/cik.c

@@ -1498,13 +1498,19 @@ static void cik_pcie_gen3_enable(struct amdgpu_device *adev)
 
 				/* linkctl2 */
 				pci_read_config_word(root, bridge_pos + PCI_EXP_LNKCTL2, &tmp16);
-				tmp16 &= ~((1 << 4) | (7 << 7));
-				tmp16 |= (bridge_cfg2 & ((1 << 4) | (7 << 7)));
+				tmp16 &= ~(PCI_EXP_LNKCTL2_ENTER_COMP |
+					   PCI_EXP_LNKCTL2_TX_MARGIN);
+				tmp16 |= (bridge_cfg2 &
+					  (PCI_EXP_LNKCTL2_ENTER_COMP |
+					   PCI_EXP_LNKCTL2_TX_MARGIN));
 				pci_write_config_word(root, bridge_pos + PCI_EXP_LNKCTL2, tmp16);
 
 				pci_read_config_word(adev->pdev, gpu_pos + PCI_EXP_LNKCTL2, &tmp16);
-				tmp16 &= ~((1 << 4) | (7 << 7));
-				tmp16 |= (gpu_cfg2 & ((1 << 4) | (7 << 7)));
+				tmp16 &= ~(PCI_EXP_LNKCTL2_ENTER_COMP |
+					   PCI_EXP_LNKCTL2_TX_MARGIN);
+				tmp16 |= (gpu_cfg2 &
+					  (PCI_EXP_LNKCTL2_ENTER_COMP |
+					   PCI_EXP_LNKCTL2_TX_MARGIN));
 				pci_write_config_word(adev->pdev, gpu_pos + PCI_EXP_LNKCTL2, tmp16);
 
 				tmp = RREG32_PCIE(ixPCIE_LC_CNTL4);
@@ -1521,13 +1527,13 @@ static void cik_pcie_gen3_enable(struct amdgpu_device *adev)
 	WREG32_PCIE(ixPCIE_LC_SPEED_CNTL, speed_cntl);
 
 	pci_read_config_word(adev->pdev, gpu_pos + PCI_EXP_LNKCTL2, &tmp16);
-	tmp16 &= ~0xf;
+	tmp16 &= ~PCI_EXP_LNKCTL2_TLS;
 	if (adev->pm.pcie_gen_mask & CAIL_PCIE_LINK_SPEED_SUPPORT_GEN3)
-		tmp16 |= 3; /* gen3 */
+		tmp16 |= PCI_EXP_LNKCTL2_TLS_8_0GT; /* gen3 */
 	else if (adev->pm.pcie_gen_mask & CAIL_PCIE_LINK_SPEED_SUPPORT_GEN2)
-		tmp16 |= 2; /* gen2 */
+		tmp16 |= PCI_EXP_LNKCTL2_TLS_5_0GT; /* gen2 */
 	else
-		tmp16 |= 1; /* gen1 */
+		tmp16 |= PCI_EXP_LNKCTL2_TLS_2_5GT; /* gen1 */
 	pci_write_config_word(adev->pdev, gpu_pos + PCI_EXP_LNKCTL2, tmp16);
 
 	speed_cntl = RREG32_PCIE(ixPCIE_LC_SPEED_CNTL);